Angular Momentum-Interesting Question.

Description
Angular momentum is defined and the fact that angular momentum is not an intrinsic property of an object unlike linear momentum is explained beautifully.An interesting example is the motion of earth for which the velocity keeps on changing but the angular momentum relative to a point does not.The relation between torque and time derivative of angular momentum is derived for a point object. The idea is extended to an extended object like a disc.It explains how spin angular momentum is an intrinsic property.Conservation of angular momentum and linear momentum is compared.The future of a star is briefly explained.When a star collapses its moment of inertia decreases. Using conservation of angular momentum the change the corresponding changes are explained.

Prof. Walter Lewin, 8.01 Physics I: Classical Mechanics, Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed June 13, 2011). License: Creative Commons BY-NC-SA: http://ocw.mit.edu/terms/#cc